The present invention relates to a combined integrated circuit/ferroelectric memory device, methods of constructing and utilizing such devices, methods for depositing ferroelectric, metal nitrate or similar materials using ion beam techniques, and methods for forming targets of ferroelectric, metal nitrate or similar materials which are used in ion beam deposition techniques.
The relevant art pertaining to integrated circuit/ferroelectric memory devices is exemplified by the following U.S. Pat. Nos.: Karan 2,803,519; Feldman 2,922,730; Bertelsen 3,110,620; Kaufman 3,142,044; Triller 3,193,408; Fatuzzo et al 3,213,027; Ostis 3,274,025; Fatuzzo 3,274,567; Fatuzzo et al 3,281,800; Kaiser et al 3,305,394; Delaney et al 3,365,631; Schuller et al 3,381,256; Nolta et al 3,405,440; Hastings 3,508,213; Galla et al 3,607,386; Carbonel 3,611,558; Sawyer 3,623,030; Lapham, Jr. et al 3,864,817; Coldren et al 3,877,982; Kobayashi 3,886,582; Francombe et al 4,047,214; Brissot et al 4,119,744; Hedel 4,195,333; Ruppel et al 4,259,365; and Ruppel et al 4,348,611; an article entitled "Ferroelectric and Other Properties of Polycrystalline Potassium Nitrate Films" by Nolta et al at pages 269-291 of a 1967 "Ferroelectricity" book edited by Edward F. Weller; a publication by Nolta et al, "Dielectric Behavior of Films of Vacuum-Deposited Potassium Nitrate," Chemical Abstracts 71:106543k, 1969; and all the art identified in Rohrer U.S. Pat. No. 4,195,355, column 1, lines 35-58.
However, none of this relevant art provides an integrated circuit/ferroelectric memory device with the characteristics of the present invention.
IBM Research Report by J. M. E. Harper, RC 8192 (#35141) 2/4/80, entitled Ion Beam Applications to Thin Films, discloses several methods of film deposition using ion beams. However, this report does not disclose that the ion beam deposition methods can be used in depositing ferroelectric, metal nitrate or similar materials.
Three articles by R. N. Castellano entitled, Ion Beam Deposition of Ferroelectric Thin Films Sputtered from Multicomponent Targets, J. Vac. Sci. Technol., 17(2), Mar/Apr 1980, pp 629-633; Deposition of Thin Films of PZT by a Focused Ion Beam Sputtering Technique, Ferroelectrics, 1980, Vol. 20, pp 387-390; and Ion-Beam Deposition of Thin Films of Lead Zirconium Titanate, J. Appl. Physics, 50(6), June 1979, pp 4406-4411, disclose a method for the deposition of Lead Zirconium Titanate [Pb(Zr.sub.x Ti.sub.1-x)O.sub.3 ] which is a mixed oxide ferroelectric material. However, the methods disclosed in these articles do not teach or suggest the use of ion beam deposition techniques for any material other than Lead Zirconium Titanate.
Additionally, these articles do not disclose or suggest the presently claimed method for forming target beds of ferroelectric, metal nitrate or similar materials, but rather discuss the use of commercially available hot pressed targets. Many ferroelectric, metal nitrate and similar materials, such as potassium nitrate, cannot be hot pressed into suitable target beds.